Pascal (unit)
(Redirected from HPa)
The pascal (symbol: Pa) is the SI-derived unit of pressure or stress. It is a measure of perpendicular force per unit area and is equal to one newton per square meter. In everyday life, the pascal is best known from meteorological air-pressure reports, where it happens in the form of hectopascal (1 hPa = 100 Pa).[1] In other cases, the kilopascal is more commonly used such as on bicycle tire labels.[2] One hectopascal corresponds to 0.1 and one kilopascal to about 1% of atmospheric pressure (near sea level).
It is named after the French mathematician and physicist Blaise Pascal.
Pascal (unit) Media
psi/kPa dial of a U.S.-style manometer for oxygen ("use no oil") under high pressuredial2
References
- ↑ World Meteorological Organization: Manual on the Global Observing System – Volume I, Section 3.3.2.2: "The hectopascal (hPa), equal to 100 pascals (Pa), shall be the unit in which pressures are reported for meteorological purposes."
- ↑ ISO 5775: Bicycle tyres and rims
